Adhesive bonding composition and method of use

Abstract

A polymerizable composition includes at least one monomer, a photoinitiator capable of initiating polymerization of the monomer when exposed to light, and a phosphor capable of producing light when exposed to radiation (typically X-rays). The material is particularly suitable for bonding components at ambient temperature in situations where the bond joint is not accessible to an external light source. An associated method includes: placing a polymerizable adhesive composition, including a photoinitiator and energy converting material, such as a down-converting phosphor, in contact with at least two components to be bonded to form an assembly; and, irradiating the assembly with radiation at a first wavelength, capable of conversion (down-conversion by the phosphor) to a second wavelength capable of activating the photoinitiator, to prepare items such as inkjet cartridges, wafer-to-wafer assemblies, semiconductors, integrated circuits, and the like.

The invention claimed is: 
     
       1. A curable adhesive composition comprising:
 an organic vehicle comprising at least one polymerizable monomer, wherein the viscosity of said organic vehicle is suitable for dispensing through an automated dispenser onto a selected substrate; 
 at least one photo-initiator responsive to a selected wavelength of light; and, 
 at least one energy converting material selected to emit said wavelength of light when exposed to a selected imparted radiation, wherein the at least one energy converting material is a downconverting material. 
 
     
     
       2. The curable adhesive of  claim 1 , wherein the imparted radiation is an ionizing radiation. 
     
     
       3. The curable adhesive of  claim 2 , wherein the ionizing radiation is X-rays. 
     
     
       4. The curable adhesive of  claim 1  wherein said organic vehicle comprises a monomer forming a thermoset resin. 
     
     
       5. The curable adhesive of  claim 4 , wherein said thermoset resin is selected from the group consisting of: acrylics, phenolics, urethanes, epoxies, styrenes, and silicones. 
     
     
       6. The curable adhesive of  claim 1 , wherein said at least one photoinitiator is selected from the group consisting of: benzoin ethers, benzil ketals, α-dialkoxyacetophenones, α-aminoalkylphenones, acylphosphine oxides, benzophenones/amines, thioxanthones/amines, and titanocenes. 
     
     
       7. The curable adhesive of  claim 1 , wherein said wavelength of light is in the UV range and said ionizing radiation comprises X-rays. 
     
     
       8. The curable adhesive of  claim 1 , wherein said downconverting material comprises dispersed inorganic particulates selected from the group consisting of: metal oxides; metal sulfides; doped metal oxides; and mixed metal chalcogenides. 
     
     
       9. The curable adhesive of  claim 1 , wherein the viscosity of said organic vehicle is suitable for printing onto a selected substrate through a mask. 
     
     
       10. The curable adhesive of  claim 1 , wherein said adhesive is photo-patternable. 
     
     
       11. The curable adhesive of  claim 1 , further comprising inorganic particulates selected from the group consisting of: metals and metal alloys, ceramics and dielectrics, and metal-coated polymers. 
     
     
       12. The curable adhesive of  claim 1 , further comprising an organic component selected from the group consisting of: solvents, viscosity modifiers, surfactants, dispersants, and plasticizers. 
     
     
       13. The curable adhesive of  claim 1 , wherein the at least one photo-initiator and the at least one energy converting material are chemically tethered to one another. 
     
     
       14. A cured adhesive formed from the curable adhesive of  claim 1 . 
     
     
       15. The cured adhesive of  claim 14 , wherein the cured adhesive is in the form of a film. 
     
     
       16. The cured adhesive of  claim 15 , wherein the cured adhesive in the form of a film is partially cured. 
     
     
       17. The cured adhesive of  claim 15 , wherein the film has anisotropic properties.